Thank you Grant...you said it better than I. The important thing is to keep the
wire out of the water.Robert,If you were to use 1 or 2 radials suspended above
the water, could you support the ends using some pipe or mast driven into the
bottom or wedged between some rocks? It just has to be above the water a
couple feet, taking into account waves and the tide. 73,Gary K9GS
-------- Original message --------From: Grant Saviers <grants2@pacbell.net>
Date: 1/8/20 4:58 PM (GMT-06:00) To: Topband@contesting.com Subject: Re:
Topband: Problems with inv L on pier over salt water Important facts about salt
water are the attenuation of a wire submerged 10" at 1MHz is -87db and at 4S/m
the conductivity is 10,000,000 times less than copper wire.Putting a single
radial in a lossy medium doesn't work very well, whether it is dirt or
saltwater. Radials elevated in low loss air work very well, especially over
salt water. They should not connect to the water just as elevated radials over
land should not be grounded.Modeling shows that one elevated radial over salt
water has a few db skew in the pattern but with 5 to 6 dbi very low angle peak
gain. With two radials the pattern is nearly perfectly symmetric.These are the
far field benefits of the ~1000x higher than earth conductivity of salt water,
so the salt water needs to extend out 5 or so wavelengths.Grant KZ1WOn 1/8/2020
12:41, Ignacy Misztal wrote:> There was a report from an expedition where the
radials in water did not> work well but over water did. Over salt water, one
radial (counterpoise) is> enough and more do not add performance.> I used
Expert 1.3k with a tuner. The amp turned itself off hundreds of> times over the
past few years due to wrong antenna or something going> wrong, with no
consequence. The way it should be.> > Ignacy, NO9E> > On Wed, Jan 8, 2020 at
2:35 PM Rik van Riel <riel@surriel.com> wrote:> >> On Wed, 2020-01-08 at 12:01
-0600, Cecil wrote:>>> I’m far from an expert but if you were over salt water I
would have>>> placed the counterpoise in the water.>>>> Word of the day: skin
depth>>>> Having the counterpoise over the water means the antenna>> current
goes through the (copper) counterpoise, of known>> resistance.>>>> Dropping the
counterpoise into the water might mean that>> the current will be split between
the counterpoise and the>> water, at an unknown (and changing with the waves
and tides)>> proportion.>>>> That could be better.>> It could also be
worse.>>>> Could it damage the antenna tuner, if it changed>> too quickly? Who
knows?>>>> Now what might make some sense is to have a few>> shorter wires come
down from the feedpoint and>> into the water, to add additional paths for the>>
current, without impeding the path through the>> counterpoise.>>>> I have no
idea how much that could help, though.>>>> -->> All Rights Reversed.>>>
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